Hear Hear!!

1. Hear Hear!! More Sound information for you.

2. Doc Ock • Remember that frequency is pitch • In music, the term octave is important and used quite often • Octave – the interval between two musical notes with half or double the frequency ex. 256 hz (C) and 512 hz (C) So the ratio is always 2:1

3. We’ve got the Beat • Sound is a wave, and therefore has all the properties of waves • Sound waves can interfere with each other, creating constructive and destructive interference • When two sound waves approach your ear with slightly different frequencies, the alternating interference can create a ‘beat’

4. They’ve got the Beat • The rate of the ‘beat’ frequency is the difference in the frequency of the original two sound waves • So, for example, if we had a frequency of 345 hz and a frequency of 351 hz, the beat frequency between them would be 6 hz (351-345)

5. All Natural • Every object has it’s own vibration that it will always vibrate at when struck • This ‘normal’ vibration is called the object’s Natural Frequency (Fundamental) • If an object has several different vibrations (harmonics / standing waves), then the first harmonic is the natural frequency

6. A Force is a Force of Course of Course • For objects to vibrate, they have to usually be ‘forced’ • This is called a Forced Vibration

7. Shake it • Imagine you are on a swing • To get yourself moving back and forth, you need to have a ‘forced vibration’ • Usually you can kick you legs back and forth • But you need to kick them at the right time • Kick them out of ‘synch’, and it doesn’t work so well • Kick them in ‘synch’, and you go higher

8. Resonators……Mount up • When a forced vibration occurs at an object’s natural frequency, the effect is known as resonance • Check it out • At these (resonant) frequencies, even a small force can result in large gains in amplitude